Performance-Based Design "Philosophy" 7

[JohnRwals]

Hello!

Performance-base design concept was introduced to architecture study long time ago.
In fact, performance concept is one of hot topics in feminism also.
I wonder anybody can explain the history of concept/terminology 'performance'.

This concept has been impacting structural engineering industry a lot including seismic design.
But, I could find many informative papers released only when this concept was discussed actively in 1990s.
Do all industries including structural engineering accept this concept?
I would like to know how this concept/methodology has influenced building codes and engineering practice.
Is there any paper or book explaining how this performance-based design has been adopted/developed HISTORICALLY
in the seismic design?

Thanks!

_JRW

 

[ggcdn]

Josh touched on retrofit uses, but on new builds PBD in the US is largely done to get around the 240ft height limit on special concrete wall systems without having to go to a dual system. One of the side effects of that, when compared to code based design, is you generally need much more shear and diaphragm reinforcing than a code based design.

It’s often portrayed as something more, and it certainly could be used for more (estimating damage under different scenarios, calculating repair costs, etc) but that seems to be the exception rather than the norm.

 

[JoshPlumSE]

Another issue is the divergence between ASCE7 and ASCE41.
Do we need to develop separate worlds between new and existing buildings?
How can we reconcile this gap?

There certainly are big differences between ASCE7 and 41.

My philosophy is this:
a) As a young engineer, the best thing to do is understand ASCE7 and all the material detailing standards for seismic design that go with it.
b) Once you understand those codes / specifications, you should see how they make a lot of assumptions about what type of non-linear behavior can be expected from the different systems. You will understand that these codes are simplifications that have been developed over the last 100 years or so to provide easy requirements to ensure good and ductile performance for various systems.
c) Only then should you begin to delve into performance based design (IMO). When you do this you will see that the methods of ASCE41 are merely more advanced and highly non-linear analysis methods that remove a lot of the simplifications you relied on in ASCE7.
d) I am wary of performance based seismic design only because it requires a much greater level of expertise from the engineer to ensure that you have a satisfactory design. It also opens the engineer up to more potential liability.
e) Maybe we should have a separate licensing system for performance based design where you have to have worked under another engineer on PBD projects for
a period of time before you can be the primary engineer on such projects. I have a feeling that's the way the firms who do this work treat it internally.

 

[JohnRwals]

I can explain my thoughts with the analogy of driverless vehicle (experiments).
I believe driverless vehicles will be everywhere some day in the future.
(This issue is related with philosophical discourse, which is 'can machines replace humans?' and how much? For a similar reason I am wondering if performance-based design is related with modern intellectual landscape like postmodernism.
Maybe many engineers are not interested with this discourse at all!)
But, I do not want to see driverless cars operating my neighbors right now.
I do not want to allow my State/County to revise related regulations to let driverless cars move in the street right now, either.
Because I do not believe driverless car industries including technology are matured enough to let them move freely and independently in the public streets.
I am interested in what is going on this area because this area can be our future, though.
Also, related industries open and share info to let people understand and know what is REALLY going on.
Otherwise, this new technology will bring about preventable social conflict and chaos.

By the same token, I acknowledge PBSD can lead future structural design.
Though many papers were released mainly in 1990s to explain the introduction of PBSD, saying why performance-based design method is better.
After publishing introductory topics, I can hardly find out papers or articles explaining how this new approach method has been evolving.
Instead, I can see many papers explaining detailed and SPECIFIC topics or methods, which require specific knowledge.
Is there any paper explaining briefly and diachronically what has been happening at this area from 1990s until 2020s with a big picture?

 

[JoshPlumSE]

I am wondering if performance-based design is related with modern intellectual landscape like postmodernism. Maybe many engineers are not interested with this discourse at all!

Yup.... I'm out.

 

[NorthCivil]

I'll never forget the wisdom given to me by my first employer (mentor).

He was an old wizard, kept on top of all the latest code issues right up until retirement. he used to review my calculations with me line by line and weigh the merits of my assumptions. i used to hate it at the time, but in hindsight, appreciate it very much.

He would often compare "the letter of the code" to the "intent of the code". And often go above code requirements, or sometimes relax them, to suit specific situations.